Method and apparatus for tightening coils of elongated material



y 17, 1962 s. B. PRELLWITZ 3,044,729

METHOD AND APPARATUS FOR TIGHTENING COILS OF ELONGATED MATERIAL 2 Sheets-Sheet 1 Filed Feb. 26, 1960 INVNTOR. 544/054 5. PRELLW/TZ W 1 JTTORNEY y 17, 1962 s. B. PRELLWITZ 3,044,729

METHOD AND APPARATUS FOR TIGHTENING COILS OF ELONGATED MATERIAL Filed Feb. 26, 1960 2 Sheets-Sheet 2 I L 25 V4 22 Pg 2 ii i IN V EN TOR.

544/062 5. PAEZZlV/l' Z ITTORIYEY United States Patent M 3,044,729 METHOD AND APPARATUS FOR TIGHTENING COILS 0F ELONGATED MATERIAL Samuel B. Prellwitz, Fallsington, Pa., assignor to United States Steel Corporation, a corporation of New Jersey Filed Feb. 26, 1960, Ser. No. 11,229 7 Claims. (Cl. 242--78.1)

The present invention relates generally to packaging apparatus and more particularly to a method and apparatus for tightening the convolutions of a coil of elongated product such as metal strip and the like preparatory to strapping the coil.

In the operation of a modern hot strip steel mill coils of hot strip produced by the mill are delivered onto a discharge conveyor in upright position with the axis of each coil extending in a vertical plane. The coils are then banded with a ring of flat metal strapping before being removed from the conveyor and transported to a storage area or subsequent processing line. Formerly, the banding was accomplished by a workman placing a length of strapping around each coil, tensioning the strapping with a conventional ratchet-type hand tool, and thenplacing a seal on the strapping to secure it around the coil. Recently, apparatus has been developed for handing the coils automatically through use of automatic banding machines. automatic banding was the looseness that developed in the outer convolutions of the coil due to vibrations set up during travel of the coil along the conveyor. Where manual banding was practiced, the heat of the coil, which was ordinarily in the vicinity of 1200" F., as it traveled along the conveyor made it impossible for the banding workmen to get close enough to the coils to tighten the outer convolutions properly before banding. As a result, the band frequently was applied too loosely and fell from the coil during subsequent handling. Similarly, where automatic banding machines were used the loose convolutions in the coil prevented the band from being applied sufliciently tight.

It is, accordingly, the primary object of my invention to provide novel means for tightening the convolutions A problem common to both manual and of a coil of elongated product in the form of apparatus which includes a plurality of radially arranged thrusters adapted to be positioned around a coil and then be operated to apply force to the periphery of a coil sequentially and intermittently along a series of spaced points therearound.

It is another object of my invention to provide apparatus as set forth in the above object which can be used in conjunction with manual banding operations as well as automatic banding mechanisms.

It is a further object of my invention to provide a method for tightening the loose convolutions of a coil of elongated material by kneading the coil progressively in one direction around its peripheral surface to thereby advance accumulated loose convolutions toward the tail.

These and other objects willbecome more apparent after referring to the following specification and attached drawing, in which:

FIGURE 1 is a top plan view;

FIGURE 2 is a side elevational view partly in section;

FIGURE 3 is a diagrammatic view of a pressure fluid cylinder of the invention and the control means therefor;

FIGURE 4 is a schematic view of the rotary switch of the invention; 7

FIGURE 5 is a diagrammatic illustration of the apparatus of the invention in one stage of its operation in tightening the outer wrap of a coil of strip material;

FIGURES 6, 7, 8, 9 and 10 are views similar to FIG- URE 5 illustrating further the sequence of operation of 3,044,729 Patented July 17, 1962 the apparatus of the invention in tightening of a coil of strip material.

Referring more particularly to the drawing reference numeral 2 designates generally the tightening apparatus of my invention which includes a ring plate 4 suspended from an overhead support (not shown) by means of rigid hanger bars 6. Six double-acting air cylinders 8 are rigidly mounted on the plate 4 in spaced relation radially therearound with the piston rods 10* thereof directed for movement toward and away from the vertical axis of the plate 4, as best shown in FIGURE 1. The ring plate 4 with the air cylinders 8 mounted thereon is adapted to be lowered over a coil C and positioned with the outer wrap the axes of the cylinders intersecting the coil C at a point" approximately halfway between its top and the bottom. Each of the piston rods 10 is provided with a pusher plate 12 on the projecting end thereof which engages the coil when the piston rod 10 is projected.

Air to each cylinder is controlled by a spring-return valve 14 which is operated by a solenoid 16. The air supply is taken through lines 18 from a manifold pipe 20, which girds the periphery of the ring plate 4 and is provided with a tap-off for each solenoid valve. A remotely located pressure air source (not shown) is connected to the manifold as at 22. (If desired, an air source with adjustable pressure may be used to control the thusting force of the air cylinder piston rods to compensate for different gauge steel coils.) The electrical power to each of the solenoids 16 is conducted by a wiring conduit 24 which, similarly to the air manifold 20, is attached to and girds the ring plate 4. A fitting 26 is provided at intervals in the conduit 24 to lead wire to each valve. A single connection is provided in the conduit as at 28, from whence the wires in the conduit are taken to a remotely located composite rotary switch 30.

Although I have shown the ring plate being suspended by arms 6, which may be attached to the ring plate as desired, it'will be understood that any desired suitable means of support or suspension may be used. For example, the' ring may rest on elevatable posts, hang from cables, be suspended from semi-rigid arms, etc. I have found it preferable to suspend the tightening apparatus of the invention from an overhead crane above a coil conveyor. In this arrangement the mechanism can be moved both vertically and horizontally to any position relative to the coil conveyor. It will also be noted that the ring plate 4 could be fixed in a position to receive the coil C for tightening. Further, the plate could be of a shape other than circular if desired, e.g. square, rectangular, etc.

The action of the piston rods 10, which function as thrusters, need not be limited to air cylinder operation. Any suitable means of supplying controlled, timed, sequential kneading action may be used. For example, hydraulic cylinders, air cylinders with spring return (rather than double-acting cylinders,), rack-and-pinion assemblies, screw-and-nut assemblies, long-stroke solenoid armatures, chain-driven racks, crank-and-crosshead assemblies, scotch yokes, or any other suitable mechanism for producing the intermittent pressure on the coil surface, whether it be a straight-line motion or a pivoted, rotary motion which accomplishes the same end, could be used if desired.

FIGURE 3 illustrates diagrammatically the arrangement of a cylinder 8, valve 14, solenoid 16 and the manifold 20. The valve 14 is a four-way valve and in one position, with the solenoid 16 inoperative, directs air from the valve inlet to the rod-end 32 of the cylinder, while air from the head-end 34 of the cylinder passes through the exhaust port of the valve. When the solenoid 16 is en ergized the action is reversedwith air from the inlet passing through the valve to the head-end of the cylinder and air from the rod-end of the cylinder passing through the valve to the exhaust port. Valve 14 is of the springreturn type so that when the solenoid is de-energized the valve is automatically returned to its original position.

As shown diagrammatically in FIGURE 4, the composite rotary switch 30 is made up of six cam roller switches 36 each of which is connected with one of the solenoids 16. The cam rollers of the switches 36 are operated by a motor-driven cam 38 which is provided with a depression in a portion of its periphery as at 40 for a purpose which will become apparent. As indicated by the arrow in FIGURE 4, the cam 3S rotates in clockwise direction and the switches 36 are normally closed when the cam rollers thereof contact the outer periphery of the cam 38. As the depression 40 in the cam periphery approaches a cam roller the roller drops into the depression 40 and the contacts of the switch open, de-energizing the solenoid coil with which the switch is connected and causing the piston rod of the cylinder controlled by that solenoid to retract.

It will be understood that the wiring of the apparatus of the invention is such that the switch 30 is remote from the ring plate 4 and'the cam switches 36 are connected by a multi-conductor cable (not shown) extending from the switch 30 to the conduit 24 which surrounds the ring.

In operation, the ring plate 4 is lowered over the coil C and positioned surrounding the mid-section of the coil with the piston rods 10 all in retracted position. After the ring plate 4 has been properly positioned, air is admitted to all of the cylinders 8 except one, which causes all but one of the piston rods 10 to be projected so that the pusher plates 12 carried thereby are thrust against the peripheral surface of the coil. The retracted piston rod corresponds with a switch 36 which is open and the looseness in the outer convolutions of the coil C is concentrated in the area adjacent the retracted piston rod. The cam 38 is then rotated so that the next piston rod in sequence is retracted and the previously retracted piston rod is projected to engage the coil. This rotates the looseness in the convolutions of the coil to the area adjacent the now retracted piston rod. As the cam 38 continues to be rotated each succeeding piston rod is retracted and then projected so that the bulged loose convolutions are forced around the coil. Each time the bulge passes the end of the outer convolution of the coil, one convolution is tightened. The cycle is repeated until all the bulges formed by the loose convolutions pass to the end of the coil and disappear leaving a tight coil. FIGURES through illustrate schematically, the progress toward the tail of a coil of a bulge formed by looseness in the outer convolution of the coil as it is being tightened by the apparatus of the invention.

The method and apparatus of the invention thus function to eliminate loose convolutions from coils of strip material in a manner that results in the production of tight coils which can be quickly and securely banded manually or by the use of automatic banding machines. The simplicity of its structural arrangement renders my invention adaptable for incorporation into the structure of an automatic banding machine as an element thereof if desired.

Although I have found it preferable to utilize six air cylinders spaced 60 apart radially of the coil, more or less than this number can be used if desired. Also, a mandrel inserted in the eye of the coil may be used, if desired, to maintain the coil in centered position relative to the ring plate 4. The pusher plate 12 is provided on the projecting end of each of the piston rods to increase contact area and to prevent the piston rod from digging into the coil surface which would restrict movement of the loose convolutions.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. Apparatus for tightening the convolutions of a coil of elongated product comprising a common support having an opening therein adapted to receive a coil, a plurality of power-operated thrusters mounted on said support in spaced relation and disposed radially of the coil, and control means effective to actuate said thrusters successively into engagement with the coil.

2. Apparatus as defined by claim 1 characterized by said control means being effective first to retract and then to advance the thrusters.

3. Apparatus as defined by claim 1 characterized by each thruster including a pressure cylinder and piston.

4. Apparatus as defined by claim 3 including a solenoid valve connected with each of said cylinders for actuating the same, and said control means including a rotary switch and a plurality of contacts successively actuatable thereby.

5. Apparatus for tightening the convolutions of a coil of elongated product comprising a ring plate adapted to be disposed circumferentially around a coil, a plurality of pressure cylinders mounted on said plate in spaced relation and disposed radially of the coil, each of said cylinders having a piston rod projecting therefrom for movement toward and away from the vertical axis of the ring plate, said piston rods being adapted to engage the periphery of said coil when projected toward the vertical axis of the ring plate, valve means on said ring plate connected with said cylinders for actuating the latter, and control means connected with said valve means for operating said pressure cylinders sequentially.

6. The method of tightening the convolutions of a coil of elongated product which consists in simultaneously applying pressure radially to the coil at more than two circumferentially spaced points, and then successively releas ing and re-applying such pressure at said points progressively around the coil.

7. The method of tightening the convolutions of a coil of elongated product which consists in simultaneously applying pressure radially to the coil at more than two equally spaced points except one, then releasing the pressure at a point adajcent said one while re-applying such pressure at said one point, and then repeating such cycle continuously around the coil.

References Cited in the file of this patent UNITED STATES PATENTS 1,882,219 Harwood et al Oct. 11, 1932 2,918,226 OBrien Dec. 22, 1959 2,928,622 Herr Mar. 15, 1960 

